This invention cocerns improvements in and relating to installation of windows.
Generally a window frame is mounted on top of a window sill, so that part of the sill extends outwardly from the window frame. At the rear of the frame i.e. inside a building, a shelf is butted up again the sill and/or the frame. Often when installing replacement u-PVC window frames, for example, the original window shelf is left in position and only a u-PVC window sill is fitted. The junction of the shelf with the sill and/or the frame needs to be masked for the sake of appearance. Even if the window shelf is also replaced, the problem of making a neat junction between the shelf and the frame still exists possibly because of irregularities in the window opening.
One proposal for dealing with this problem was made in GB 2287273A, which describes a window frame system comprising a window shelf abutting a window sill member, a window frame mounted on a part of the window sill member and a beading strip for masking the junction of the window shelf with the window fame and/or sill, wherein the beading strip comprises a cover piece and a channel section depending from the cover piece located on an upstand of the window frame system, whereby the beading strip is locatable in position after assembly of the window frame shelf and sill.
Even this arrangement is not entirely satisfactory because of the possible unevenness of a window opening causing the beading not to seal properly along its entire length. Furthermore, there is no possibility of adjusting the lateral position of the frame relative to the window sill.
An object of this invention is to provide a solution to the above-mentioned problems of window installation.
According to this invention it is proposed that a combined window shelf and sill be provided i.e. as a one-piece construction. Preferably the combined window shelf and sill is formed by extrusion of plastics material, especially u-PVC.
The preferred combined window shelf and sill of the invention has a top wall and a bottom wall connected by webs to form ducts therethrough. At its window shelf end the combined component is preferably shaped to provide a rounded top edge profile and preferably has a return on its underside.
At its window sill end, the combined component preferably has a downwardly sloping top wall leading to an overhang extending below the bottom wall of the component whereby water falling on the sill can drop off the overhang rather than travel back along the underside of the component and into the supporting brickwork.
Between the shelf and sill parts, the combined component has a part on which a window frame can be mounted. That part preferably has means for lateral adjustment in the positioning of the frame relative to the shelf/sill. By lateral adjustment is meant adjustment normal to the plane of the window. Preferably the combined component has a series of locations for a locating element that also locates in a part of the window frame. The window frame can have a channel or slot on its underside and the combined component can have a sense of parallel slots in its top sure, whereby a peg, strip or the like can locate in the frame and one of the slots of the combined component according to the desired position of the window frame relative to shelf/sill component.